Family mobile plans in Japan: 5 ways to cut the bill for four

Japan family mobile plan: ¥4,268 to ¥14,212 a month for four at 10 GB each
Aeon and IIJmio share data; UQ mobile, Rakuten and Y!mobile cut each line
Noon speed: UQ mobile 110.50 Mbps, IIJmio 5.87

The five

Best for	Where to get it	Score	Monthly, four people
One allowance shared by the whole family, and the cheapest total here — if you can’t decide	Aeon Mobile Get it	72/100	¥4,268 (per month for four)
Different allowances per person, pooled within the month	IIJmio Get it	71/100	¥4,450 (per month for four)
Fast at midday, and the light users’ lines fall by themselves	UQ mobile Get it	70/100	¥13,992 (per month for four)
Everyone discounted, grandparents included, and calls between you free	Rakuten Mobile Get it	69/100	¥8,272 (per month for four)
Fast, with the largest per-line discount — from the second line	Y!mobile Get it	68/100	¥14,212 (per month for four)

These are Japanese services. Where a plan needs a Japanese address, a bank account or a residence card, we say so on the row itself.

One allowance shared by the whole family, and the cheapest total here

Aeon Mobile

You set the household’s total data, not each person’s
A shop inside Aeon is the easiest place to set up a child’s first phone

See plans and prices→

Why it made the five

One data allowance shared across up to eight SIMs on a single contract
Allowances from 1 GB to 200 GB, so you can size it to the household
Over 200 shops inside Aeon stores, where the whole family can be dealt with at once
Docomo or au network, your choice
Right for: Having an Aeon nearby, and wanting all the family’s phones on one contract.
Not for: Needing speed at lunchtime — independent operators slow when the network is busy.
Worth knowing: Prices are from the published April 2024 list. A paid filtering service is required for under-18s. Check the current price before you apply.

Score breakdown — 72/100

Criterion	Stars	Why
Quality	★★☆☆☆	Docomo or au. 6.01 Mbps at noon on the Docomo line
Value for money	★★★★★	¥4,268 a month: ¥3,388 for a 40 GB share plan, plus ¥220 and ¥220 for the second and third SIMs and ¥440 for the fourth
Easy to live with	★★★☆☆	Over 200 shops; filtering is paid (¥220–396); no child discount on the price list
Trust	★★★★☆	Third in MMD Labo’s August 2026 MVNO satisfaction survey (766) and fourth by independent-SIM share at March 2026
Only here	★★★★☆	Up to eight SIMs sharing one allowance, sized anywhere from 1 GB to 200 GB

Different allowances per person, pooled within the month

IIJmio

Largest independent operator in Japan
Give the heavy user a big bundle, everyone else a small one

See plans and prices→

Why it made the five

Lines under the same account share that month’s data, whatever allowance each one has
Two or more voice lines earn a discount on all of them
Eight allowances from 2 GB to 55 GB
Docomo or au network
Right for: A family whose usage varies a lot, wanting the lowest possible total.
Not for: Wanting the internet to be quick at midday, or wanting a shop to go to.
Worth knowing: Both sharing and the discount require the lines to be under the same account holder. The discount must be applied for, and you must agree to receive IIJmio’s emails.

Score breakdown — 71/100

Criterion	Stars	Why
Quality	★★☆☆☆	Docomo or au. 5.87 Mbps at noon on the Docomo line
Value for money	★★★★★	¥4,450 a month: ¥2,000 for 25 GB plus ¥950 × 3 for 5 GB, less ¥100 × 4. Four equal 10 GB lines would be ¥5,200
Easy to live with	★★☆☆☆	No shops of its own; filtering is paid (¥396); no child discount found
Trust	★★★★★	First by independent-SIM share at March 2026 and first as a main MVNO in MMD Labo’s August 2026 survey; third in J.D. Power 2025
Only here	★★★★☆	The only plan here letting each person hold a different allowance and still pool the month’s data

Fast at midday, and the light users’ lines fall by themselves

UQ mobile

au’s second brand
Fastest line of all at six in the evening
Works best with more light users in the household

See plans and prices→

Why it made the five

The family discount covers every line, including the first
Any line using 5 GB or less in a month is reduced automatically
Free content filtering for under-18s
UQ Spot and au shops handle families in person
Right for: Wanting real speed while still paying less for the family members who barely use it.
Not for: Four people all using 10 GB or more with no home-internet bundle — the total is high.
Worth knowing: The family discount and the home bundle cannot be combined. A relative with a different surname or address must be registered at a shop with documents. Only four lines can be registered in My UQ mobile.

Score breakdown — 70/100

Criterion	Stars	Why
Quality	★★★★★	au network. 110.50 Mbps at noon, and 101.88 at 18:00 — first of fourteen lines
Value for money	★☆☆☆☆	¥13,992 a month: (¥4,048 − ¥550) × 4. Lines under 5 GB fall a further ¥1,100
Easy to live with	★★★★☆	Shops, and free filtering; the parent-and-child discount closed in May 2026
Trust	★★★★★	First in J.D. Power 2025’s value-carrier category (645, tied with Y!mobile); 9.5% of main-line users in MMD Labo’s August 2026 survey
Only here	★★★★☆	The only plan here that automatically reduces an individual line in a month when that person used little

Everyone discounted, grandparents included, and calls between you free

Rakuten Mobile

Runs its own network
Monthly price moves in three steps with each person’s usage
Grandparents can join the group

See today’s price on Rakuten→

Why it made the five

Every line discounted, with no requirement to live together, up to twenty lines in a group
Free domestic calls through the Rakuten Link app, including to each other
The bill falls by itself in a month under 3 GB
An extra discount of up to ¥440 a month for children up to 12
Right for: A family that telephones each other, or that wants to include grandparents elsewhere.
Not for: Needing a dependable signal deep inside buildings or underground.
Worth knowing: Calls are free only from the Rakuten Link app. A contract for an under-18 requires the ¥550 parental control service.

Score breakdown — 69/100

Criterion	Stars	Why
Quality	★★★☆☆	Rakuten’s own network. 12.53 Mbps at noon
Value for money	★★★☆☆	¥8,272 a month: (¥2,178 − ¥110) × 4. A line under 3 GB costs ¥968
Easy to live with	★★★★☆	Shops nationwide and a child discount; filtering costs ¥550
Trust	★★★★☆	Third in MMD Labo’s August 2026 survey of nine carrier brands (726); 10.8% of main-line users
Only here	★★★★☆	A family group of up to twenty lines with no address requirement, and free calls between them

Fast, with the largest per-line discount — from the second line

Y!mobile

SoftBank’s second brand, and it held its speed at midday
Shops move a whole family across in one visit
With SoftBank Hikari or SoftBank Air at home, the home bundle saves more than the family discount

See plans and prices→

Why it made the five

Second and subsequent family lines discounted, up to nine lines
Relatives by blood or marriage qualify even at a different address
Free content filtering for under-18s
Shops nationwide, and the fastest app download speed measured at noon
Right for: Putting speed and a shop counter first, and moving the whole family at once.
Not for: Wanting the lowest possible total for four.
Worth knowing: The family discount cannot be combined with the SoftBank Hikari bundle or other offers. Simple 3 base prices changed on 2 June 2026.

Score breakdown — 68/100

Criterion	Stars	Why
Quality	★★★★★	SoftBank network. 123.03 Mbps at noon, third of fourteen lines, and first for app downloads at that hour
Value for money	★☆☆☆☆	¥14,212 a month: ¥4,378 for the first line plus (¥4,378 − ¥1,100) × 3
Easy to live with	★★★★☆	Shops and free filtering; the parent-and-child discount closed in June 2026
Trust	★★★★★	First in J.D. Power 2025’s value-carrier category (645, tied with UQ mobile); 11.2% of main-line users
Only here	★★★☆☆	The largest per-line discount here, and relatives count even when they live elsewhere — though the mechanism itself is not unusual

Know before you buy

A family discount reduces the monthly price of each line. Shared data instead pools one allowance, so the heavy user and the light user balance each other out.
Priced for four people at 10 GB each, the range here is enormous: ¥4,268 at the cheapest and ¥14,212 at the dearest, for the same amount of data.
What you pay for is speed. The independents are a third of the price and a twentieth of the midday speed — IIJmio measured 5.87 Mbps at noon against UQ mobile’s 110.50.
Bundling with home fibre changes the picture: Y!mobile takes ¥1,650 off each line with a SoftBank Hikari bundle, UQ mobile ¥1,100 — but neither stacks with the family discount.
Children under 18 are expected by law to use content filtering. It is free at Y!mobile and UQ mobile, and ¥220–550 a month everywhere else.
Who counts as family differs: Rakuten does not require you to live together and allows twenty lines; UQ mobile wants documents at a shop for a relative at another address.

How we chose: theme, conditions, scoring

How we chose

Candidates: 15
Met every condition below: 7
Kept: five, each the best at something different

Conditions (all of them, not most of them)

Has a per-line family discount or data sharing, usable without also buying home internet or television
The monthly total for four people at 10 GB each can be worked out from the published price list
Includes a voice line with a Japanese number, and can be taken as an eSIM
Accepting new customers as of September 2026

Scoring

Five criteria, one to five stars each, weighted to one hundred points. Every star says where the number came from.

Quality25 pts
- From Kakaku.com Magazine’s March 2026 field measurements, using the noon average download speed. 100 Mbps or more is five stars, 50 four, 10 three, 3 two, below that one.
Value for money30 pts
- The monthly total for a family of four at 10 GB each, including tax. Only family discounts and data sharing are applied — no home-internet bundles, card discounts or limited-time offers. Under ¥5,000 is five stars, ¥7,500 four, ¥10,000 three, ¥12,500 two, above that one.
Easy to live with20 pts
- Starts at two stars, since all of them sell online and as eSIMs. Add one each for shops of their own where a family can be dealt with in person, for free content filtering for under-18s, and for a child discount still open in September 2026.
Trust15 pts
- Placings in J.D. Power’s 2025 study, MMD Labo’s August 2026 survey and MM Research’s operator share at March 2026. First is five stars, second or third four, otherwise three.
Only here10 pts
- How far the thing only this operator does for families cannot be had elsewhere. Our judgement, with the reason stated.

What we dropped

Candidate	Verdict	Why
mineo	Runner-up (59/100)	59 points, below the lowest of the five (68)
BIGLOBE Mobile	Runner-up (37/100)	37 points, below the lowest of the five (68)
ahamo	Outside the theme	An ahamo line counts towards a Docomo family group’s line total but is not itself discounted, and there is no data sharing.
LINEMO and povo2.0	Outside the theme	Fast at midday, but neither has a family discount or data sharing.
Nihon Tsushin SIM	Outside the theme	Its own FAQ states that data sharing is not available, and there is no family discount.
Docomo mini	Outside the theme	Its discounts depend on paying by dCard or bundling Docomo Hikari, home 5G or electricity — the plan itself has no family discount or data sharing. OCN Mobile ONE has stopped taking new customers.
J:COM MOBILE	Outside the theme	Its data-boost for the whole family requires a J:COM internet, television or electricity contract — there is no family discount for the phones alone.

Questions visitors ask

What is the cheapest way to put four phones on 10 GB each?

Aeon Mobile’s share plan, at ¥4,268 a month for 40 GB between four, and IIJmio at ¥4,450 using its family discount and data sharing. Rakuten comes to ¥8,272, UQ mobile ¥13,992 and Y!mobile ¥14,212 for the same data. The gap is speed: the two cheapest are a twentieth as fast at lunchtime.

Does bundling with home internet help?

Substantially. Y!mobile’s SoftBank Hikari bundle takes ¥1,650 off each line, bringing four Simple 3 M lines to ¥10,912. UQ mobile’s home bundle takes ¥1,100 off each, bringing four lines to ¥11,792. Neither can be combined with the family discount, and both require a qualifying internet or electricity contract.

Family discount or shared data — what is the difference?

A family discount cuts the monthly price of each line: Y!mobile, UQ mobile, Rakuten, IIJmio, mineo. Shared data pools an allowance instead: IIJmio lets lines under one account pass that month’s data between them, Aeon Mobile splits one allowance across up to eight SIMs, and mineo shares last month’s carried-over data across up to ten lines.

Do children need content filtering, and does it cost?

For under-18s, filtering is expected by law. It is free at Y!mobile and UQ mobile. Elsewhere it is monthly: Rakuten ¥550, IIJmio ¥396, mineo ¥385, Aeon Mobile ¥220–396, BIGLOBE ¥220.

Can relatives living elsewhere join?

It varies. Y!mobile accepts relatives by blood or marriage at a different address. UQ mobile does too, but the registration has to be done at a shop with documents proving the relationship. Rakuten’s family discount has no address requirement at all and allows twenty lines in a group. mineo covers relatives within three degrees of the main line. IIJmio requires the lines to share one account.

Why aren’t ahamo, LINEMO and povo here?

All three are fast at midday and all three are worth considering for one person — 134.40, 80.33 and 79.32 Mbps at noon. But none of them has a family discount or data sharing built into the plan, which fails our first condition.

Changes

2026-10-25　First published. Scored from 15 candidates.